org.h2.index

Class BaseIndex

java.lang.Object

org.h2.engine.DbObjectBase

org.h2.schema.SchemaObjectBase

org.h2.index.BaseIndex

All Implemented Interfaces:

DbObject, Index, SchemaObject

Direct Known Subclasses:

FunctionIndex, HashIndex, LinkedIndex, MetaIndex, MVDelegateIndex, MVPrimaryIndex, MVSecondaryIndex, MVSpatialIndex, NonUniqueHashIndex, PageIndex, RangeIndex, ScanIndex, SpatialTreeIndex, TreeIndex, ViewIndex

public abstract class BaseIndex
extends SchemaObjectBase
implements Index

Most index implementations extend the base index.

Field Summary

Fields

Modifier and Type	Field and Description
protected int[]	columnIds
protected Column[]	columns
protected IndexColumn[]	indexColumns
protected IndexType	indexType
protected boolean	isMultiVersion
protected Table	table

Fields inherited from class org.h2.engine.DbObjectBase

comment, database, trace

Fields inherited from interface org.h2.engine.DbObject

AGGREGATE, COMMENT, CONSTANT, CONSTRAINT, FUNCTION_ALIAS, INDEX, RIGHT, ROLE, SCHEMA, SEQUENCE, SETTING, SYNONYM, TABLE_OR_VIEW, TRIGGER, USER, USER_DATATYPE

Constructor Summary

Constructors

Constructor and Description
BaseIndex()

Method Summary

Modifier and Type	Method and Description
boolean	canFindNext() Check if the index can get the next higher value.
boolean	canScan() Can this index iterate over all rows?
protected static void	checkIndexColumnTypes(IndexColumn[] columns) Check that the index columns are not CLOB or BLOB.
void	commit(int operation, Row row) Commit the operation for a row.
int	compareRows(SearchRow rowData, SearchRow compare) Compare two rows.
IndexLookupBatch	createLookupBatch(TableFilter[] filters, int filter) Creates new lookup batch.
Cursor	find(TableFilter filter, SearchRow first, SearchRow last) Find a row or a list of rows and create a cursor to iterate over the result.
Cursor	findNext(Session session, SearchRow higherThan, SearchRow last) Find a row or a list of rows that is larger and create a cursor to iterate over the result.
int	getColumnIndex(Column col) Get the index of a column in the list of index columns
Column[]	getColumns() Get the indexed columns.
protected long	getCostRangeIndex(int[] masks, long rowCount, TableFilter[] filters, int filter, SortOrder sortOrder, boolean isScanIndex, java.util.HashSet<Column> allColumnsSet) Calculate the cost for the given mask as if this index was a typical b-tree range index.
java.lang.String	getCreateSQL() Build a SQL statement to re-create this object.
java.lang.String	getCreateSQLForCopy(Table targetTable, java.lang.String quotedName) Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table
java.lang.String	getDropSQL() Build a SQL statement to drop this object.
protected DbException	getDuplicateKeyException(java.lang.String key) Create a duplicate key exception with a message that contains the index name.
IndexColumn[]	getIndexColumns() Get the indexed columns as index columns (with ordering information).
IndexType	getIndexType() Get the index type.
java.lang.String	getPlanSQL() Get the message to show in a EXPLAIN statement.
Row	getRow(Session session, long key) Get the row with the given key.
Table	getTable() Get the table on which this index is based.
int	getType() Get the object type.
protected void	initBaseIndex(Table newTable, int id, java.lang.String name, IndexColumn[] newIndexColumns, IndexType newIndexType) Initialize the base index.
boolean	isFindUsingFullTableScan() Returns true if find() implementation performs scan over all index, false if find() performs the fast lookup.
boolean	isFirstColumn(Column column) Check if the given column is the first for this index
boolean	isHidden() Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.
boolean	isRowIdIndex() Does this index support lookup by row id?
protected boolean	mayHaveNullDuplicates(SearchRow searchRow) Check if this row may have duplicates with the same indexed values in the current compatibility mode.
void	removeChildrenAndResources(Session session) Remove all dependent objects and free all resources (files, blocks in files) of this object.
void	setSortedInsertMode(boolean sortedInsertMode) Enable or disable the 'sorted insert' optimizations (rows are inserted in ascending or descending order) if applicable for this index implementation.

Methods inherited from class org.h2.schema.SchemaObjectBase

getSchema, getSQL, initSchemaObjectBase

Methods inherited from class org.h2.engine.DbObjectBase

checkRename, getChildren, getComment, getDatabase, getId, getModificationId, getName, initDbObjectBase, invalidate, isTemporary, isValid, rename, setComment, setModified, setObjectName, setTemporary, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.h2.index.Index

add, canGetFirstOrLast, close, find, findFirstOrLast, getCost, getDiskSpaceUsed, getRowCount, getRowCountApproximation, needRebuild, remove, remove, truncate

Methods inherited from interface org.h2.schema.SchemaObject

getSchema

Methods inherited from interface org.h2.engine.DbObject

checkRename, getChildren, getComment, getDatabase, getId, getName, getSQL, isTemporary, rename, setComment, setTemporary

Field Detail

indexColumns

protected IndexColumn[] indexColumns

columns

protected Column[] columns

columnIds

protected int[] columnIds

table

protected Table table

indexType

protected IndexType indexType

isMultiVersion

protected boolean isMultiVersion

Constructor Detail

BaseIndex

public BaseIndex()

Method Detail

initBaseIndex

protected void initBaseIndex(Table newTable,
                             int id,
                             java.lang.String name,
                             IndexColumn[] newIndexColumns,
                             IndexType newIndexType)

Initialize the base index.

Parameters:

newTable - the table

id - the object id

name - the index name

newIndexColumns - the columns that are indexed or null if this is not yet known

newIndexType - the index type

checkIndexColumnTypes

protected static void checkIndexColumnTypes(IndexColumn[] columns)

Check that the index columns are not CLOB or BLOB.

Parameters:

columns - the columns

getDropSQL

public java.lang.String getDropSQL()

Description copied from class: DbObjectBase

Build a SQL statement to drop this object.

Specified by:

getDropSQL in interface DbObject

Specified by:

getDropSQL in class DbObjectBase

Returns:

the SQL statement

getDuplicateKeyException

protected DbException getDuplicateKeyException(java.lang.String key)

Create a duplicate key exception with a message that contains the index name.

Parameters:

key - the key values

Returns:

the exception

getPlanSQL

public java.lang.String getPlanSQL()

Description copied from interface: Index

Get the message to show in a EXPLAIN statement.

Specified by:

getPlanSQL in interface Index

Returns:

the plan

removeChildrenAndResources

public void removeChildrenAndResources(Session session)

Description copied from class: DbObjectBase

Remove all dependent objects and free all resources (files, blocks in files) of this object.

Specified by:

removeChildrenAndResources in interface DbObject

Specified by:

removeChildrenAndResources in class DbObjectBase

Parameters:

session - the session

canFindNext

public boolean canFindNext()

Description copied from interface: Index

Check if the index can get the next higher value.

Specified by:

canFindNext in interface Index

Returns:

true if it can

isFindUsingFullTableScan

public boolean isFindUsingFullTableScan()

Description copied from interface: Index

Returns true if find() implementation performs scan over all index, false if find() performs the fast lookup.

Specified by:

isFindUsingFullTableScan in interface Index

Returns:

true if find() implementation performs scan over all index, false if find() performs the fast lookup

find

public Cursor find(TableFilter filter,
                   SearchRow first,
                   SearchRow last)

Description copied from interface: Index

Find a row or a list of rows and create a cursor to iterate over the result.

Specified by:

find in interface Index

Parameters:

filter - the table filter (which possibly knows about additional conditions)

first - the first row, or null for no limit

last - the last row, or null for no limit

Returns:

the cursor to iterate over the results

findNext

public Cursor findNext(Session session,
                       SearchRow higherThan,
                       SearchRow last)

Find a row or a list of rows that is larger and create a cursor to iterate over the result. The base implementation doesn't support this feature.

Specified by:

findNext in interface Index

Parameters:

session - the session

higherThan - the lower limit (excluding)

last - the last row, or null for no limit

Returns:

the cursor

Throws:

DbException - always

getCostRangeIndex

protected final long getCostRangeIndex(int[] masks,
                                       long rowCount,
                                       TableFilter[] filters,
                                       int filter,
                                       SortOrder sortOrder,
                                       boolean isScanIndex,
                                       java.util.HashSet<Column> allColumnsSet)

Calculate the cost for the given mask as if this index was a typical b-tree range index. This is the estimated cost required to search one row, and then iterate over the given number of rows.

Parameters:

masks - the IndexCondition search masks, one for each column in the table

rowCount - the number of rows in the index

filters - all joined table filters

filter - the current table filter index

sortOrder - the sort order

isScanIndex - whether this is a "table scan" index

allColumnsSet - the set of all columns

Returns:

the estimated cost

compareRows

public int compareRows(SearchRow rowData,
                       SearchRow compare)

Description copied from interface: Index

Compare two rows.

Specified by:

compareRows in interface Index

Parameters:

rowData - the first row

compare - the second row

Returns:

0 if both rows are equal, -1 if the first row is smaller, otherwise 1

mayHaveNullDuplicates

protected boolean mayHaveNullDuplicates(SearchRow searchRow)

Check if this row may have duplicates with the same indexed values in the current compatibility mode. Duplicates with NULL values are allowed in some modes.

Parameters:

searchRow - the row to check

Returns:

true if specified row may have duplicates, false otherwise

getColumnIndex

public int getColumnIndex(Column col)

Description copied from interface: Index

Get the index of a column in the list of index columns

Specified by:

getColumnIndex in interface Index

Parameters:

col - the column

Returns:

the index (0 meaning first column)

isFirstColumn

public boolean isFirstColumn(Column column)

Description copied from interface: Index

Check if the given column is the first for this index

Specified by:

isFirstColumn in interface Index

Parameters:

column - the column

Returns:

true if the given columns is the first

getCreateSQLForCopy

public java.lang.String getCreateSQLForCopy(Table targetTable,
                                            java.lang.String quotedName)

Description copied from interface: DbObject

Build a SQL statement to re-create the object, or to create a copy of the object with a different name or referencing a different table

Specified by:

getCreateSQLForCopy in interface DbObject

Parameters:

targetTable - the new table

quotedName - the quoted name

Returns:

the SQL statement

getCreateSQL

public java.lang.String getCreateSQL()

Description copied from class: DbObjectBase

Build a SQL statement to re-create this object.

Specified by:

getCreateSQL in interface DbObject

Specified by:

getCreateSQL in class DbObjectBase

Returns:

the SQL statement

getIndexColumns

public IndexColumn[] getIndexColumns()

Description copied from interface: Index

Get the indexed columns as index columns (with ordering information).

Specified by:

getIndexColumns in interface Index

Returns:

the index columns

getColumns

public Column[] getColumns()

Description copied from interface: Index

Get the indexed columns.

Specified by:

getColumns in interface Index

Returns:

the columns

getIndexType

public IndexType getIndexType()

Description copied from interface: Index

Get the index type.

Specified by:

getIndexType in interface Index

Returns:

the index type

getType

public int getType()

Description copied from interface: DbObject

Get the object type.

Specified by:

getType in interface DbObject

Returns:

the object type

getTable

public Table getTable()

Description copied from interface: Index

Get the table on which this index is based.

Specified by:

getTable in interface Index

Returns:

the table

commit

public void commit(int operation,
                   Row row)

Description copied from interface: Index

Commit the operation for a row. This is only important for multi-version indexes. The method is only called if multi-version is enabled.

Specified by:

commit in interface Index

Parameters:

operation - the operation type

row - the row

getRow

public Row getRow(Session session,
                  long key)

Description copied from interface: Index

Get the row with the given key.

Specified by:

getRow in interface Index

Parameters:

session - the session

key - the unique key

Returns:

the row

isHidden

public boolean isHidden()

Description copied from interface: SchemaObject

Check whether this is a hidden object that doesn't appear in the meta data and in the script, and is not dropped on DROP ALL OBJECTS.

Specified by:

isHidden in interface SchemaObject

Overrides:

isHidden in class SchemaObjectBase

Returns:

true if it is hidden

isRowIdIndex

public boolean isRowIdIndex()

Description copied from interface: Index

Does this index support lookup by row id?

Specified by:

isRowIdIndex in interface Index

Returns:

true if it does

canScan

public boolean canScan()

Description copied from interface: Index

Can this index iterate over all rows?

Specified by:

canScan in interface Index

Returns:

true if it can

setSortedInsertMode

public void setSortedInsertMode(boolean sortedInsertMode)

Description copied from interface: Index

Enable or disable the 'sorted insert' optimizations (rows are inserted in ascending or descending order) if applicable for this index implementation.

Specified by:

setSortedInsertMode in interface Index

Parameters:

sortedInsertMode - the new value

createLookupBatch

public IndexLookupBatch createLookupBatch(TableFilter[] filters,
                                          int filter)

Description copied from interface: Index

Creates new lookup batch. Note that returned IndexLookupBatch instance can be used multiple times.

Specified by:

createLookupBatch in interface Index

Parameters:

filters - the table filters

filter - the filter index (0, 1,...)

Returns:

created batch or null if batched lookup is not supported by this index.